Researchers at Purdue University have identified a new class of chemical insecticides. This new class should provide a safer and more selective means of controlling mosquitoes. A new class is needed to key infectious diseases such as dengue, yellow fever and elephantiasis.

According to Catherine Hill, professor of entomology and Showalter Faculty Scholar, researchers used the mosquito genome to pinpoint chemicals that will be more selective than current insecticides, which bind readily to molecules in humans and non-target insects. Know as dopamine receptor antagonists (DAR antagonists), “these are sophisticated designer drugs,” she said. “They’re like personalized medicine for mosquitoes — but in this case, the medicine is lethal.”

Hill’s team showed that the “designer drugs” have high potency for both the larval and adult stages of the Aedes aegypti mosquito. This species of mosquito transmits yellow fever, dengue and chikungunya and Culex quinquefasciatus, West Nile virus and the disfiguring disease elephantiasis. Effective pest control measures are important as they slow the spread of mosquito-borne diseases. But “overuse of antibiotics and insecticides has led to the rise of drug-resistant strains of infectious diseases and the emergence of mosquitoes that can withstand conventional pesticides, a “double whammy,” Hill said.

“There’s an urgent need for new insecticides,” she said. “We are seeing a resurgence of infectious diseases that for the last 50 years we had the luxury of controlling with antibiotics and modern medicine. These diseases are increasingly going to become a problem for people everywhere.”

The team is mining a group of about 200 DAR antagonists to find the most promising chemicals for commercial products. The insecticides could be cost-effective compared with current products and would have low environmental impact because of their selectivity, Hill said.

Similar protein receptors are apparent in the African malaria mosquito, the sand fly and the tsetse fly. This suggests to researchers that DAR antagonists could be implemented to control these disease-transmitting insects. “We’re going after all the big ones,” Hill said.